Money in Peru?

All costs for Peru which I come across during researching are stated in American dollars. Think accommodation, the inca trail, etc.However, the value of the American dollar has been steadily declining for the last couple of years (at least compared to the euro), and doesn't seem set to stop doing so anytime soon, which leaves me wondering about how much things will actually cost me.

How closely linked to the American dollar is the Peruvian (nuevo) sol? Is the dollar declining in value compared to the sol as well? And the Peruvian sol is what I should be expecting to use to actually pay for things, right? (That is, even though accommodation prices are listed in US dollars, I'd pay the equivalent in soles, rather than needing to carry actual American currency with me?)Has anyone ever had trouble where they were expecting to pay the listed price in USD, and suddenly been asked for an additional 10-20% because of declining rates?Anything else relevant that anyone could tell me about this?

I found it really cheap when I was out there, I bought pretty much everything in Sols only using dollars a couple of times so I can't say whether prices were cheaper or not than normal. I certainly didn't notice any signs about surcharges for dollars or hear of people being asked for more because they were paying in dollars.

I'd advise taking GBP/Euros changing them as you need them. You can also use the plentiful cash machines in major towns, though a couple of people did warn about using globanet apparently they're reknowned for fraud...

I think is wise to carry some Euros to Peru. You can change them into soles in Lima city. The dollar is declining many months ago. You can use dollars and even euros in most of the cities, and dollars and soles in every touristic service or place among peru.